<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        let arr = ['apple', 'banana', 'orange']
        let b = arr.includes('banana');
        let c = arr.includes('cc');
        let d = arr.includes(null);
        let e = arr.includes(arr[6]);

        console.log(b); // true
        console.log(c); // false
        console.log(d); // false
        console.log('e-', e);
        // ---------------------------------------

        let ar = [{
            name: 'zs0',
            age: 10
        }, {
            name: 'zs2',
            age: 12
        }, {
            name: 'zs4',
            age: 14
        }, {
            name: 'zs5',
            age: 15
        }, {
            name: 'zs6',
            age: 16
        }]
        let ars = ar.filter((val) => {
            return val.name === 'zs4'
        });
        console.log(ars);
    </script>
</body>

</html>